<?php
/**
  * wechat php test
  */

//define your token
define("TOKEN", "07dccb2cfb50dfad0e94d7099c461dc8");
$wechatObj = new wechatCallbackapiTest();
$wechatObj->responseMsg();

class wechatCallbackapiTest{
	public function valid(){
        $echoStr = $_GET["echostr"];

        //valid signature , option
        if($this->checkSignature()){
        	echo $echoStr;
        	exit;
        }
    }
    public function log($data){
        file_put_contents("data.log", $data,FILE_APPEND);
    }

    public function responseMsg(){
		//get post data, May be due to the different environments
		$postStr = $GLOBALS["HTTP_RAW_POST_DATA"];
        $this->log($postStr);

      	//extract post data
		if (!empty($postStr)){
            /* libxml_disable_entity_loader is to prevent XML eXternal Entity Injection,
               the best way is to check the validity of xml by yourself */
            libxml_disable_entity_loader(true);
          	$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
            $fromUsername = $postObj->FromUserName;
            $toUsername = $postObj->ToUserName;
            $type = $postObj->MsgType;
            $keyword = trim($postObj->Content);
            $time = time();
            $textTpl = "<xml>
				<ToUserName><![CDATA[%s]]></ToUserName>
				<FromUserName><![CDATA[%s]]></FromUserName>
				<CreateTime>%s</CreateTime>
				<MsgType><![CDATA[%s]]></MsgType>
				<Content><![CDATA[%s]]></Content>
				<FuncFlag>0</FuncFlag>
				</xml>";
            if ($type=='event'&&$type->Event=="subscribe"){
                $msgType = "text";
                $contentStr = "欢迎您的关注！";
                $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
                echo $resultStr;            
            }                         
			if( $keyword =="你好"){
          		$msgType = "text";
                $contentStr = '<a href="http://www.baidu.com">点我</a>';
            	$resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
            	echo $resultStr;
            }
            if ($keyword =="图文"){
                $Articles=array(array(
                    'Title'=>"新安",
                    'Description'=>"新安人才网",
                    'PicUrl'=>"http://www.goodjobs.cn/images/logo.gif",
                    'Url'=>"http://www.goodjobs.cn/",
                    ),array(
                    'Title'=>"万家热线",
                    'Description'=>"万家热线",
                    'PicUrl'=>"http://www.365jia.cn/images/www/site_logo.gif",
                    'Url'=>"http://www.365jia.cn/",
                    ),array(
                    'Title'=>"新安晚报",
                    'Description'=>"新安网",
                    'PicUrl'=>"http://img.ahwang.cn/templates/ahwang/css/images/logo.png",
                    'Url'=>"http://www.ahwang.cn/",
                    ),array(
                    'Title'=>"人民日报",
                    'Description'=>"人民网",
                    'PicUrl'=>"http://www.people.com.cn/img/2016people/images/rmw_logo.png",
                    'Url'=>"http://www.people.com.cn/",
                    ),
                );
                $textTpl = "<xml>
                    <ToUserName><![CDATA[%s]]></ToUserName>
                    <FromUserName><![CDATA[%s]]></FromUserName>
                    <CreateTime>%s</CreateTime>
                    <MsgType><![CDATA[news]]></MsgType>
                    <ArticleCount>%s</ArticleCount>
                    <Articles>";
                        foreach ($Articles as $a) {
                        $textTpl.="<item>
                            <Title><![CDATA[".$a['Title']."]]></Title> 
                            <Description><![CDATA[".$a['Description']."]]></Description>
                            <PicUrl><![CDATA[".$a['PicUrl']."]]></PicUrl>
                            <Url><![CDATA[".$a['Url']."]]></Url>
                        </item>";
                        }
                        $textTpl.="</Articles>
                </xml>"; 
                $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time,count($Articles));
                echo $resultStr;
            }
        }else {
        	echo "";
        	exit;
        }
    }
		
	private function checkSignature(){
        // you must define TOKEN by yourself
        if (!defined("TOKEN")) {
            throw new Exception('TOKEN is not defined!');
        }
        
        $signature = $_GET["signature"];
        $timestamp = $_GET["timestamp"];
        $nonce = $_GET["nonce"];
        		
		$token = TOKEN;
		$tmpArr = array($token, $timestamp, $nonce);
        // use SORT_STRING rule
		sort($tmpArr, SORT_STRING);
		$tmpStr = implode( $tmpArr );
		$tmpStr = sha1( $tmpStr );
		
		if( $tmpStr == $signature ){
			return true;
		}else{
			return false;
		}
	}
}
?>